Fluororubbers are used as industrial materials in a wide variety of technical fields, since they have much better heat-resistance, oil-resistance, solvent-resistance, chemical-resistance, etc. than general-purpose rubbers.
Fluororubbers are often used under severe conditions such as a temperature of 200° C. by making use of their particularly good heat-resistance. However, for achieving heat-resistance under such severe conditions, it is inevitable to mold the curable composition of fluororubbers, subjecting the molded article to primary curing and then subjecting the cured article to secondary curing to complete crosslinking and to release gasses generated in the course of crosslinking.